1. Field of the Invention
The present invention relates to a method for securing an overdenture in an oral position and to an improved overdenture structure. More specifically, the invention relates to the securing of an overdenture by magnetic attraction between the overdenture and the remaining natural teeth. The nerves of the remaining natural teeth are removed and the roots filled with dental paste as in a root canal treatment. The crowns of the teeth are removed and ferromagnetic material is embedded in the roots.
Overdentures are artificial dentures which attach over one or more natural teeth which have had the crowns removed and the roots filled as in a root canal treatment. It has long been known in dentistry that overdentures are preferred over ordinary artificial dentures. Thus, if the dentist determines that one or more of the patient's natural teeth can be saved, a root canal treatment is performed and the crowns of those teeth are removed. The remaining portions of the natural teeth are then ground to provide a contoured mating surface with the overdenture. The overdenture is then formed to fit over the residual ridge of the patient and over the remaining natural teeth which have been subjected to the above treatment. An advantage of an overdenture is that it permits the patient to apply a much greater biting pressure before pain is induced. Furthermore, the retention of one or more natural teeth prevents resorption of the jaw bone.
2. Description of the Prior Art.
In normal dental practice, an overdenture is secured by reliance on conventional adhesive and cohesive forces created by the close fitting of the overdenture to the residual ridge. When such normal retention is not available because of factors peculiar to the patient, adhesives are used.
Commercially available adhesives lose their adherence over a period of time. The adhesive most frequently fails when a patient is either talking or eating, thus subjecting the patient to embarrassment. Furthermore, adhesives create unsanitary conditions in the patient's mouth which can be irritating and damaging.
Mechanical attachments, such as the Zest anchor, are available to secure overdentures. These mechanical means are fragile and make the removal of the overdenture cumbersome.
The present invention is directed to an improved overdenture and to a method employing magnetic attraction for securing an overdenture to the residual ridge which eliminates the problems presented by the use of adhesives and mechanical attachments.
U.S. Pat. Nos. 2,543,773 and 2,555,392 disclose the use of magnets embedded close to the biting surface of ordinary artificial dentures. The magnets are embedded in respective upper and lower artificial dentures and aligned so that identical poles of the magnets are opposite one another. The resulting repelling forces of the magnets push the dentures against the residual ridges of the patient, thus serving to aid in securing the artificial dentures in the oral position.
U.S. Pat. Nos. 3,514,859 discloses a magnet surgically implanted into the body of the jaw bone and opposing a second magnet of opposite polarity which is attached to an ordinary artifical denture.